Storm Warning 22, NWS Juneau, AK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
515 AM AKST Sun Nov 19 2023

.SHORT TERM.../Rather quiet night across the panhandle as the
front over the southern panhandle is finally getting pushed out of
the area. Rain has mostly ended for the southern panhandle (except
Hyder), and significant breaks in the cloud cover have developed.
Northerly outflow winds have developed with min gale force winds
down Lynn Canal and 25 to 30 kt in other areas like Stephens
Passage and out of the passes near Yakutat. These northerly winds
have also brought a colder air mass into the area with several
areas in the northern half of the panhandle below freezing this
morning.

Through Sun night, the forecast is the calm before the storm. The
outflow winds this morning are expected to diminish somewhat as
northerly pressure gradients slacken due to ridging over the
panhandle. However, they are expected to restrengthen rapidly
early Monday as the next storm approaches from the south.
Temperatures will also be colder than what we had seen over the
last week with highs in the north today struggling to get above
freezing.

By late Sunday night, a storm force low will be entering the
south central Gulf. A strong front extending east across the Gulf
and over the southern Panhandle by Monday morning. In this classic
overrunning scenario, Precip will begin as snow and the front
will move north over the Panhandle through Monday night. Snowfall
will be heavy at times and a winter storm watch was issued with
the Saturday afternoon forecast. Snow totals for this 27 hour
period of time may reach 10 to 16 inches with the highest totals
north of Sumner Strait and south of the Chilkat Peninsula. Highest
uncertainty in snow amounts will be for the Kupreanof and Kuiu
Island areas as temperatures could warm enough for a rain/snow mix
rather then all snow Monday afternoon affecting snow totals.

In addition to the expected winter weather, the strength of this
front has prompted a high wind watch for Prince of Wales Island
Monday and Monday night with wind gusts to 60 mph. Strong gusts
are also expected for Ketchikan and Annette Island. Apart from
winds associated with the front, the northerly pressure gradient
may result in a mountain wave event for downtown Juneau with gusts
to 50 mph possible as well as strong outflow winds for the
various northern inner channels and NE gulf coast.

.LONG TERM.../Tuesday through Friday morning/ As mentioned in the
short range, the storm force low in the Gulf will be moving north
and is expected to turn northwest on Tuesday. Outflow winds will
continue through Tuesday, and combined with the storm force low in
the Gulf, will result in continued gales for most of the inside
waters. For more information on see the Marine Section below. As
the low in the gulf eventually pushes off to the west, rain and
snow showers will continue across the panhandle for the majority
of the week with persistent southerly onshore flow. Overall
looking to be progressively warmer from south to north for most of
the panhandle for the second half of the week as well.

&&

.AVIATION...VFR conditions exist across most of the panhandle this
morning with decreasing cloud cover. The exception to this is the
eastern portions of the central and southern panhandle where
cloud cover is more extensive on satellite imagery. Although most
places are VFR, there are some locations reporting occasional MVFR
and even some IFR conditions with passing snow showers off the
gulf. An outflow pattern continues to develop during the TAF
period allowing for more clearing but increased wind speeds out of
gaps in terrain that lead into Canada. CIGs across the southern
panhandle are expected to decrease towards the end of the TAF
period as the next system starts to move into the area.

&&

.MARINE...Strong northerly outflow winds will develop in Lynn
Canal beginning late Sunday night building to sustained winds of
up to 50 kt by Monday morning. Winds to gale force are expected
out of the Taku inlet as well as to N Chatham Strait, and blowing
out of Cross Cross Sound. With the location of the storm force low
in the Gulf, similarly strong outflow winds of up to 50 kt are
expected out of Yakutat Bay by Monday morning and gales persisting
through most of Tuesday.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Strong Wind late tonight for AKZ318.
     Winter Storm Watch from Monday afternoon through late Monday
     night for AKZ318-319.
     Winter Storm Watch from late tonight through late Monday night
     for AKZ320>322-324-325.
     Winter Storm Watch from late tonight through Monday morning for
     AKZ326-327.
     High Wind Watch from late tonight through late Monday night for
     AKZ328.
MARINE...Gale Warning for PKZ012-013-053-641>644-661>664.
     Small Craft Advisory for PKZ021-022-031>036-651-652-671-672.

&&

SHORT TERM...EAL
LONG TERM....STJ
AVIATION...SF

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